Poor Man's Nutrients Control - Donovan's Nitrate Destroyer

[Colin_S]

WOW, ,, I've just finished reading every post.... What a thread BTW.
1st off, Thank you Donovan, wherever you may be. You leave behind a legacy to share information and give our time to others. Too many people take and rarely give back. I was so shocked to read about Donovan's death only a day after he was active on the forum helping people.. R.I.P

Someone touched on this only a few pages back and no one really followed up on it or responded to him. Something i had been thinking for a while.
There is so much good information on the DND, especially in early post. All the info is there, yet it seems to be getting lost within bundles of post. So many repeated questions, the most obvious one being what to do when the effluent starts to smell,,, increase the flow.. if you take the time to read the info that Donovan was kindly enlough to share with us you'll find most if not all the answers. Which leads me onto my original point.
What was mentioned previously was to take all the information required and keep it one place so its not lost within the thread, the longer the thread goes on, the less likely people will read all of it. You could link this thread at the bottom of it so it can be discussed without getting lost..

What makes me laugh when people say there DT is 5-10ppm and they want to lower them! 5-10 i wish i had that, thats my target lol.. Currently i have 80-100ppm, this got me researching nitrate reduction and found this thread. i have media in the sump, but as I now know, I'm using it wrong. So I'm building my own DND, 4"/110mm pipe at about 18" high. It will be built and filled with media suggested by Donovan. i'm only targeting No3, I have ATS for Po4

I have just bought the pipe work, need a few more bits and media before It goes into action. One thing I am a bit sketchy on is seeding it. if someone could explain step by step I would appreciate it, I get the irony asking for an explination given what ive just wrote lol. I'm pretty sure i have most thing covered, but time will tell.
This is what I've understood with seeding
Seed the media with bacteria for 5 days, inside the destroyer. How much bacteria ml per 24hours?
Let it sit inside the destroyer for a few hours (3hrs?) Then what? Do you flush through the destroyer, at what rate and into DT/Sump?

I'm going to re-Read the fisrt quarter of the thread to pick up on anything I've missed

 

[Aqua Man]

Letting sit idle for a few hrs probably wouldn’t hurt. Each DND is a little different. Seed with bacteria, I would follow instructions on bottle for your tank size. Letting it flow into sump or tank should be ok. Add bacteria for a few days to seed and dial in the flow. Flow seems the hardest to nail down. I would start on the higher side. I don’t remember the recommendation for flow. After bacteria has been seeded for a few days then the Carbon source is added daily.

 

[Colin_S]

I've made my DND, and its currently cycling, i used vibrant reef, to begin with, but have ordered Brightwell Microbacter 7. I filled it with live rock small/medium sizes and siporax cermaic rings.
Flow was recommended between 5-10% daily turn over.
Will use Red Sea no-pox as carbon dose. after a 3 days of seeding.

A couple of issue, I sprung a leak in 2 places. 1 at the top. A bit of added glue solved that, and where the 2 Chambers connect. Added plumbers tape around the thread and that solved that.

Second issue, is. The pressure is forcing the water back up the dosing tube. I'm hoping once the dosing tube is connected to the auto doser and the tube is filled with no/pox it wont back feed. but any tips is welcomed. not sure moving the inlets/outlets and dosing tube is feasible due to them being on flat surfaces. but if i have to..

once i start carbon dosing i'll post back with my results.
currently tank is at 80-100ppm nitrates.. nothing i've done has helped. i'm confident this will work.
Size is 110mm (4") x 17" High.
I'm going to reduce the effluents size to 1/4"

 

[Colin_S]

cycling

 

[Aqua Man]

Is the outlet lower than inlet? Hard to tell from pictures. The connection between the 2 towers could also be creating the back pressure, looks narrow there.

 

[Colin_S]

the outlet is slightly lower but not much. it will be hard to lower it, but not impossible. The connection between the 2 sides is meant to be reduced 1", to slow the flow rate and reduce the air. Something Donovan mentions a few times in the early posts. i think lowering the lutlet may be my only choice.

 

[Colin_S]

so, i dosed using the dosing tube, only bennifical bacteria, just to see how it acted. i used a syringe connected it to the tubing and there was very, if not no back pressure. as soon as i started pushing down on the plunger the liquid went into the cannister. i'm hopefull now that once its hooked up to the auto doser and primmed, it will have no issues.. fingers crossed.

 

[Colin_S]

So today I tested the reactor, 24hrs after I started dosing no-pox. i dose 1ml 5x a day on a auto doser. I didn't test 1hr after it dosed I justed to test it anyway and guess what!
First drop in no3! can't believe it.
DT 180ppm
DND 40-60ppm
a noticeable change in colour comparing the 2, not sure its as obvious in the pictures though.. super happy.. I'll let it run for s few more days then increase the dosage if the no3 is still at 40-60ppm

Again, thank you Donovan where ever u may be

 

[DancingWind]

So today I tested the reactor, 24hrs after I started dosing no-pox. i dose 1ml 5x a day on a auto doser. I didn't test 1hr after it dosed I justed to test it anyway and guess what!
First drop in no3! can't believe it.
DT 180ppm
DND 40-60ppm
a noticeable change in colour comparing the 2, not sure its as obvious in the pictures though.. super happy.. I'll let it run for s few more days then increase the dosage if the no3 is still at 40-60ppm

Again, thank you Donovan where ever u may be

100+ ppm drop in 1 day? emm .. you might want to slow down a bit ... granted the damage is already done

 

[Colin_S]

I'm dosing 5ml and flow rate at 10% per 24hrs. The dt is still at 180ppm (the highest the chart reads). Until I see the dt dropping I'll leave it be for a week. I'm sure I read on the early post you want 0 from the effluent then increase the flow to increase the no3 to your desired target ppm

 

[Colin_S]

36 hours later i tested the No3. I tested 1hr before dosage. sucess, the reactor is giving out 0 No3.. DT has dropped as well from 160ppm to 65 ish. OP states to test 1hr after dosing but i wanted to see what the reactor was outputting so i'm well happy. I'll wait for the dt to reach 40ppm before dialing in the reactor. my No3 target is 10-15ppm

 

[Afterburner]

A while ago I had high nitrates and tried to build a suitcase version of the Donovan reactor, but my build leaked due to my relatively sloppy acrylic cutting and poor gluing. While I was building it I had bought a doser for the project and hooked it up to my cra

 

[Afterburner]

Crazy high 80+ nitrate tank using NoPoX. Before I could get the suitcase reactor to quit leaking, my nitrates dropped to almost zero so I removed the dosing of NoPoX and my Nitrates stayed at around 2 for at least 6 months. I then had a magnet rust and zinc went sky high killing my birds nest first, then hammers, torch, candy canes before I did an ICP and found the issue. As my tank started to recover, my PO4 and NO3 climbed up to 0.20 PO4, and 25 NO3 which caused a cyno outbreak. I did some chemiclean a couple of times and then decided to just fix the nutrient issue so I hooked up my doser with NoPoX and in a little over a week I have my PO4 around 0.03 and NO3 at 2.5 which seems OK to me. The moral of my story, or at least what I have found is that I think that you really don't need to build a Donovan reactor, just do some sort of carbon dosing with some bio media in your sump or a decent sand bed and it will build up a good bio filter that will work even after you turn off the carbon dosing. I did find that I really needed to use a doser to get it to work because I just could not dose accurately by hand. I am sort of glad my attempt to make a Donovan reactor failed since it is just one more think that could break or leak or need cleaning down the road. I will probably remove my NoPox dosing this week and see if the NO3 stays low like it did before. I am convinced my PO4 dropped because of the recent coral growth and a little bit due to the NoPoX.

 

[Colin_S]

i remember read your suitcase build,, good effort.
For me, i had dosed no-pox, i have a 2-3" sand bed, Skimmer, Turf Scrubber and had media in the sump. No3 still was over 160ppm.
Obviously i don't know no where near as much as Donovan did, but from what i've learned is, for denitrification to take place, you need anerobic enviroment which is a very low flow, pourous media and carbon source. Something you can't always get in a sump but cn achieve i the reactor.

Sometimes like yourself just dosing seems to work, but not for me. Having a reactor i can fine tune it, and know whats going back into the DT. Which i can prove.
I changed the flow into my reactor by mistake, tested again this morning and the DT and Reactor are both at 60-70ppm. i tested yesterday with the correct flow and the reactor was at 0ppm. This proves to me that flow plays a major factor in the results. When i was just dosing no-pox into the sump/DT i saw no drop in No3, when the reactor was outputting 0ppm at 1% per 24hrs the DT dropped from 160ppm to 80ish ppm, so even at such a small % it made a difference, which i never saw just dosing.

This reactor is just another option for someone to use should they need it. If you don't have no3 issues then you wont need it. but for me its been a game changer.
Back to my flow,,, I have reduced the reactor to 5% 200ml / min and will see how it goes.

 

[Afterburner]

i remember read your suitcase build,, good effort.
For me, i had dosed no-pox, i have a 2-3" sand bed, Skimmer, Turf Scrubber and had media in the sump. No3 still was over 160ppm.
Obviously i don't know no where near as much as Donovan did, but from what i've learned is, for denitrification to take place, you need anerobic enviroment which is a very low flow, pourous media and carbon source. Something you can't always get in a sump but cn achieve i the reactor.

Sometimes like yourself just dosing seems to work, but not for me. Having a reactor i can fine tune it, and know whats going back into the DT. Which i can prove.
I changed the flow into my reactor by mistake, tested again this morning and the DT and Reactor are both at 60-70ppm. i tested yesterday with the correct flow and the reactor was at 0ppm. This proves to me that flow plays a major factor in the results. When i was just dosing no-pox into the sump/DT i saw no drop in No3, when the reactor was outputting 0ppm at 1% per 24hrs the DT dropped from 160ppm to 80ish ppm, so even at such a small % it made a difference, which i never saw just dosing.

This reactor is just another option for someone to use should they need it. If you don't have no3 issues then you wont need it. but for me its been a game changer.
Back to my flow,,, I have reduced the reactor to 5% 200ml / min and will see how it goes.

How much NoPoX did you dose when you did not have the reactor running? I just did the recommended dosage on the container and split it into two dosing a day. I also have one of those porous bricks in my sump that may make the difference. Since you have a Donovan reactor working, I guess this is a moot point anyway. I don't remember my NO3 every being as high as yours even when it was a Fish only tank. Even now I have a pretty heavy load with over 20 fish in my 90G DT and 20G display Fuge. My sump is pretty small (15G) due to the limited space under my corner tank with only a Skimmer and Santa Monica Drop 1.4 algae scrubber. I think all the corals help keep my nutrients in order as I noticed a spike when I had a zinc issue that killed a bunch and stopped growth for a few months. Here are a couple of pic of my DT and Fuge

 

[Colin_S]

nice looking tank,,
I do have a marine pure block, but i have it in fast flow to deal with ammonia cycle.
My issue was, i never really dealt with nitrate before, i thought the LR dealt with it like nitrite & ammonia.
When starting your first tank there a lot to take in and this just passed me by.
When i started taking no3 seriously, about a year ago (only had tank for 2.5yrs) i was using nyos, and i kept getting readings of 25ppm, always 25, never changed. i changed test kits to Red sea pro and it was off the chart, 64ppm is the max. I added the API test kit, not as reliable but goes upto 160ppm. and it was at 160ppm.
i was dosing no-pox the recommended amout every other day, but this dropped my po4 to 0 then i had a massive algae outbreak. I did add sera siporax and seachem de-nitrate but this did very little. It felt that i was loosing the battle and thats when i started researching heavyily. I came across this thread which just seemed right up my street and would yield results, which it did..
Now i feel i can get control of the no3.
I learned so much reading this thread now i feel i understand it a lot better. For example, i had read about putting media in a reactor, so i did. Using my gfo dual reactor i replaced the media with my de-nitrate media, tested the outlet every few days and still no3 matched DT.This was like it this for weeks. I had the flow way to fast going through the reactor something i didn't know about or the reason why the flow needs to be low, something i learned here.
Moral of the story, had i known everything i know now, maybe i wouldn't need the DND, but its definetley a good tool to have or know about.

 

[Afterburner]

I agree, I learned a lot reading the 50+ pages of interesting implementations and the late Donovan's comments/theory of operation. The reason I was trying to make a suitcase unit was because of the limited room I have under my tank. I wanted something very compact that would not need to be in my tiny sump. My plan was to dose the carbon at the input to the pump feeding the device so it could be a sealed unit that sat on the floor behind the cabinet. I came really close to getting it working, but figured I would always worry about flooding my house if it started leaking. If I ever have the time to try it again, I will use thicker acrylic (1/4") and probably be fine. I may also just make a PVC version that is a single column pressurized version since it would be easier to seal and super quick to make. That is if my Nitrates ever go crazy and NoPoX doesn't work for me. I also would probably use moonshine filtered through a Britta carbon filter a few time as the carbon source since it is cleaner than vodka.

 

[Colin_S]

little update, i've increased the flow from the DND to 15%. Still getting 0PPM. DT has dropped fro 180ppm to 20ppm now.. i would say this has been a massive success.. i'm going to really dial in the reactor in the next week or so, so that the DT is at 10ppm and so is DND, i'll probably do this by reducing carbon dosing from 5ml

 

[Afterburner]

little update, i've increased the flow from the DND to 15%. Still getting 0PPM. DT has dropped fro 180ppm to 20ppm now.. i would say this has been a massive success.. i'm going to really dial in the reactor in the next week or so, so that the DT is at 10ppm and so is DND, i'll probably do this by reducing carbon dosing from 5ml

It seems like everyone tries the flow rate, but has anyone tried increasing the carbon dose instead and see what happens. I would imagine that once the carbon dose is too high, there will be some carbon that comes out into the tank and you would get your tank operating like the DND and reducing the nitrates even further.

 

[Colin_S]

15% was too much flow and DND wasn't producing 0 ppm. So i've dialed it back in to 10% and back at 0ppm.
My aim is to have the DT at 5-10ppm, i'm not sure what i need the DND to be in order to achieve this. So i'll leave it at 0ppm and see where the tank goes, then dial back if need be.

It seems like everyone tries the flow rate, but has anyone tried increasing the carbon dose instead and see what happens. I would imagine that once the carbon dose is too high, there will be some carbon that comes out into the tank and you would get your tank operating like the DND and reducing the nitrates even further.

I'm not sure what benifits you get from over dosing? maybe too much carbon can have a negative affect? If the DND is producing 0 ppm, eventually you'll be able to have the No3 in the DT at your target ppm, why over dose?